The present invention relates to an exercise device, particularly but not exclusively to a dumbbell or barbell for weight lifting exercises and other fitness activities.
Conventional dumbbells or barbells comprise a bar and a set of weights mounted on the end portions of the bar. These dumbbells or barbells further comprise flanges and collars to retain the weights in position on the bar and to secure the weights. The flanges are provided on the bar towards the end portions. The collars are located on the end portions of the bar, over the weights, and are used to secure the weights on the bar by cooperating with the flanges to secure the weights therebetween.
These dumbbells or barbells have the problem that, through repeated use, the collars can become loose, thereby causing the weights to rotate, wobble and vibrate around the handle during use. This results in the dumbbell becoming awkward to use, and can eventually cause the weights to become disconnected from the bar, which can be extremely hazardous to the user.
Prior art patent GB2410197 addresses this problem by providing a dual fixing mechanism. The dumbbell of GB2410197 is provided with first and second securing members for securing the weight assembly to the end portion of the bar. The first securing member is a locking nut, which co-operates with a threaded portion on the bar, to force the weight against a flange section.
The second securing member comprises an end plate which engages with the weight. The end plate sits over the weight, and is held in place by means of a mounting screw, which engages with an internal thread in the end portion of the bar.
However, it has been noted that this fixing mechanism may still loosen in use due to the manner in which the dumbbells are treated by the user. In use, dumbbells are frequently dropped to the floor by their users, and will often land on their ends. It has been observed that the forces exerted by such a dropping action can result in excessive lateral, and rotational movement of the end plate, which in turn results in loosening of the securing members.